scholarly journals A Numerical Investigation on Emissions of Partially Premixed Shale Gas Combustion

2020 ◽  
Vol 38 (3) ◽  
pp. 745-751
Author(s):  
Suat Ozturk
Keyword(s):  
Shale Gas ◽  
Inlet Temperature ◽  
Ansys Software ◽  
Humidity Ratio ◽  
Gas Combustion ◽  
Flow Rates ◽  
Swirl Velocity ◽  
Mass Fractions ◽  
Partially Premixed ◽  
No Emissions

The adiabatic, turbulent, and partially premixed combustions of several shale gases and air in a co-axial type combustor are computationally examined under the effects of different equivalence ratios, inlet temperatures, flow rates, humidity ratios, pressure, oxid inlet temperatures and flow rates, and swirl velocities in this study. Shale gases are extracted from Barnette, New Albany, Fayetteville, and Haynesville areas of USA. ANSYS software is used for numerical calculations of combustion. Results show that the maximum NO emissions for Barnette, New Albany, Fayetteville, and Haynesville shale gas occur at the equivalence ratio of 1.42, 1.41, 1.4, and 1.39. The rising fuel inlet temperature increase NO and reduces CO emissions after 300 K. The increasing humidity ratio causes NO and CO mass fractions to decrease. The ascending pressure raises NO up to 4 bar and lowers CO emissions. The increasing oxid flow rate abates the mass fractions of both NO and CO. The rising swirl velocity escalates NO up to 15 m/s and decreases CO emissions for all the shale gas combustions.

scholarly journals Effects of CO2, H2O and N2 Dilutions on Emission Characteristics and Partially Premixed Combustion of Shale Gas

2019 ◽  
Vol 8 (6) ◽  
pp. 4440-4446
Keyword(s):  
Shale Gas ◽  
Energy Production ◽  
Turbulent Flame ◽  
Emission Characteristics ◽  
Partially Premixed Combustion ◽  
Mass Fractions ◽  
Pressure Increment ◽  
Partially Premixed ◽  
Dilution Effects ◽  
Gas Fields

Environmental constraints of countries on hazardous emissions promote the usage of gas fuels in combustion systems for energy production. The shale gas recently shines out as one of the promising gas fuels of the future owing to its wide reserves discovered in the different gas fields of countries. This study numerically focuses on the emission characteristics and turbulent adiabatic combustion of partially premixed shale gas and humid air with dilution effects of CO2, H2O, and N2 under different pressures. Ansys codes are used for the numerical computations of computational fluid dynamics on 2D model of a co-axial type combustor to find out the emissions and flame speeds during the combustion of shale gas and air. Based on the results, the maximum NO mass fractions are obtained at 1.42, 1.44, and 1.4 equivalence ratios for Barnette, New Albany, and Haynesville. The increasing equivalence ratio raises the mass fractions of CO and turbulent flame speeds. The rising CO2 dilution into the additional air diminish the flame speeds, NO and CO fractions. The growing H2O addition decreases NO and CO mass fractions. On the contrary, it augments the flame speeds. The enhancing N2 dope decreases NO and rears CO mass fractions. The rising pressure with 15% CO2 dilution fades up the turbulent flame speeds, NO and CO fractions. The pressure increment with 15% H2O dope reduces CO and the flame speeds. But, it lightly relieves NO fractions. The growing pressure with 15% N2 addition abates the mass fractions of CO and turbulent flame speeds.

Multiflame Patterns in Swirl-Driven Partially Premixed Natural Gas Combustion

2002 ◽  
Vol 125 (1) ◽  
pp. 40-45 ◽  
Author(s):  
K. P. Vanoverberghe ◽  
E. V. Van den Bulck ◽  
M. J. Tummers ◽  
W. A. Hu¨bner
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Flow ◽  
State Transition ◽  
Gas Combustion ◽  
Bifurcation Phenomena ◽  
Major Species ◽  
Partially Premixed ◽  
Natural Gas Combustion ◽  
Low Nox Emission

Five different flame states are identified in a compact combustion chamber that is fired by a 30 kW swirl-stabilized partially premixed natural gas burner working at atmospheric pressure. These flame states include a nozzle-attached tulip shaped flame, a nonattached torroidal-ring shaped flame (SSF) suitable for very low NOx emission in a gas turbine combustor and a Coanda flame (CSF) that clings to the bottom wall of the combustion chamber. Flame state transition is generated by changing the swirl number and by premixing the combustion air with 70% of the natural gas flow. The flame state transition pathways reveal strong hysteresis and bifurcation phenomena. The paper also presents major species concentrations, temperature and velocity profiles of the lifted flame state and the Coanda flame and discusses the mechanisms of flame transition and stabilization.

Design Analysis of a Micro Gas Turbine Combustion Chamber Burning Natural Gas

2012 ◽  
Author(s):  
André Perpignan V. de Campos ◽  
Fernando L. Sacomano Filho ◽  
Guenther C. Krieger Filho
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Low Cost ◽  
Mixture Fraction ◽  
Combustion Model ◽  
Inlet Temperature ◽  
Gas Combustion ◽  
Micro Turbine

Gas turbines are reliable energy conversion systems since they are able to operate with variable fuels and independently from seasonal natural changes. Within that reality, micro gas turbines have been increasing the importance of its usage on the onsite generation. Comparatively, less research has been done, leaving more room for improvements in this class of gas turbines. Focusing on the study of a flexible micro turbine set, this work is part of the development of a low cost electric generation micro turbine, which is capable of burning natural gas, LPG and ethanol. It is composed of an originally automotive turbocompressor, a combustion chamber specifically designed for this application, as well as a single stage axial power turbine. The combustion chamber is a reversed flow type and has a swirl stabilized combustor. This paper is dedicated to the diagnosis of the natural gas combustion in this chamber using computational fluid dynamics techniques compared to measured experimental data of temperature inside the combustion chamber. The study emphasizes the near inner wall temperature, turbine inlet temperature and dilution holes effectiveness. The calculation was conducted with the Reynolds Stress turbulence model coupled with the conventional β-PDF equilibrium along with mixture fraction transport combustion model. Thermal radiation was also considered. Reasonable agreement between experimental data and computational simulations was achieved, providing confidence on the phenomena observed on the simulations, which enabled the design improvement suggestions and analysis included in this work.

scholarly journals Heat transfer enhancement of car radiator using aqua based magnesium oxide nanofluids

2015 ◽  
Vol 19 (6) ◽  
pp. 2039-2048 ◽  
Author(s):  
Hafiz Ali ◽  
Muhammad Azhar ◽  
Musab Saleem ◽  
Qazi Saeed ◽  
Ahmed Saieed
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Thermal Management ◽  
Heat Transfer Performance ◽  
Inlet Temperature ◽  
Fluid Temperature ◽  
Transfer Enhancement ◽  
Volumetric Concentration ◽  
Flow Rates ◽  
Transfer Rates

The focus of this research paper is on the application of water based MgO nanofluids for thermal management of a car radiator. Nanofluids of different volumetric concentrations (i.e. 0.06%, 0.09% and 0.12%) were prepared and then experimentally tested for their heat transfer performance in a car radiator. All concentrations showed enhancement in heat transfer compared to the pure base fluid. A peak heat transfer enhancement of 31% was obtained at 0.12 % volumetric concentration of MgO in basefluid. The fluid flow rate was kept in a range of 8-16 liter per minute. Lower flow rates resulted in greater heat transfer rates as compared to heat transfer rates at higher flow rates for the same volumetric concentration. Heat transfer rates were found weakly dependent on the inlet fluid temperature. An increase of 8?C in inlet temperature showed only a 6% increase in heat transfer rate.

Effects of Taper Configurations on Heat Transfer and Pressure Drop in Single-Phase Flows in Microgaps

2020 ◽  
Author(s):  
Debora C. Moreira ◽  
Gherhardt Ribatski ◽  
Satish G. Kandlikar
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Pressure Drop ◽  
Single Phase ◽  
Bubble Nucleation ◽  
Low Flow ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Inlet Section ◽  
Flow Rates

Abstract This paper presents a comparison of heat transfer and pressure drop during single-phase flows inside diverging, converging, and uniform microgaps using distilled water as the working fluid. The microgaps were created on a plain heated copper surface with a polysulfone cover that was either uniform or tapered with an angle of 3.4°. The average gap height was 400 microns and the length and width dimensions were 10 mm × 10 mm, resulting in an average hydraulic diameter of approximately 800 microns for all configurations. Experiments were conducted at atmospheric pressure and the inlet temperature was set to 30 °C. Heat transfer and pressure drop data were acquired for flow rates varying from 57 to 485 ml/min and the surface temperature was monitored not to exceed 90 °C to avoid bubble nucleation, so the heat flux varied from 35 to 153 W/cm2 depending on the flow rate. The uniform configuration resulted in the lowest pressure drop, and the diverging one showed slightly higher pressure drop values than the converging configuration, possibly because the flow is most constrained at the inlet section, where the fluid is colder and presents higher viscosity. In addition, a minor dependence of pressure drop with heat flux was observed due to temperature dependent properties. The best heat transfer performance was obtained with the converging configuration, which was especially significant at low flow rates. This behavior could be explained by an increase in the heat transfer coefficient due to flow acceleration in converging gaps, which compensates the decrease in temperature difference between the fluid and the surface due to fluid heating along the gap. Overall, the comparison between the three configurations shows that converging microgaps have better performance than uniform or diverging ones for single-phase flows, and such effect is more pronounced at lower flow rates, when the fluid experiences higher temperature changes.

Droplet-Particle Agglomeration of Maltodextrin and Salt in a Small-Scale Spray Dryer

2008 ◽  
Vol 4 (6) ◽  
Author(s):  
Tim Langrish ◽  
D. Ali ◽  
M. Asplet
Keyword(s):  
Small Scale ◽  
Inlet Temperature ◽  
Scanning Electron Micrographs ◽  
Spray Dryer ◽  
Particle Agglomeration ◽  
Collision Efficiency ◽  
Flow Rates ◽  
Air Inlet ◽  
Two Fluid ◽  
Scanning Electron

The technique of in-chamber blending in practice has been investigated, by altering the configuration of a Buchi B290 small-scale spray dryer having a two-fluid nozzle, through adding an extra pipe into the chamber to agglomerate maltodextrin (DE18) particles with 20% salt solution sprayed through the atomizer. Scanning Electron Micrographs showed the importance of splash impacts between salt droplets and maltodextrin particles in this geometry, suggesting that the collision efficiency is strongly affected by whether or not the salt droplets completely surround the dry maltodextrin particles. Changing the air inlet temperature did not affect the measured amount of collisions (from Atomic Absorption Spectroscopy) significantly, but both the main air and the nozzle air flow rates had significant effects on the collision outcomes.

scholarly journals Effect of Desiccant Solution Temperature on Regeneration Performance of a Cross-Flow Regenerator

2019 ◽  
Vol 111 ◽  
pp. 01086
Author(s):  
Hye-Won Dong ◽  
Hye-Jin Cho ◽  
Jae-Weon Jeong
Keyword(s):  
Aqueous Solution ◽  
Cross Flow ◽  
Optimal Solution ◽  
Experimental Tests ◽  
Coefficient Of Performance ◽  
Solution Temperature ◽  
Inlet Temperature ◽  
Humidity Ratio ◽  
Temperature And Humidity ◽  
The Cross

The purpose of this study is to investigate the effect of the inlet solution temperature on the performance of an adiabatic cross-flow regenerator using a lithium chloride (LiCl) aqueous solution, and to propose the optimal inlet solution temperature when operating this type of regenerator. In the experimental tests, the inlet solution temperature range varied from 50 to 90°C. The tests were carried out at 10°C intervals while the other conditions remained constant. The measurement parameters for the test were the inlet air dry-bulb temperature and humidity ratio, outlet air dry-bulb temperature and humidity ratio, air volume flow, solution density, and inlet and outlet solution temperatures. The regeneration effectiveness and coefficient of performance (COP) were selected to assess the heat and mass transfer performance of the cross-flow regenerator. The most important finding of this research was to determine the optimal solution inlet temperature in the cross-flow regenerator with the LiCl aqueous solution considering both the regenerator performance and energy consumption. The test results show that the recommended inlet solution temperature is 60°C, considering both regeneration effectiveness and COP.

Theoretical Performance of Silica Gel Desiccant Wheel

2019 ◽  
Vol 7 (3) ◽  
pp. 66-74
Author(s):  
Zainab Mahdi Salih ◽  
Abdulsalam D. M.Hassan ◽  
Amer Majeed Al-Dabagh
Keyword(s):  
Silica Gel ◽  
Air Temperature ◽  
Inlet Temperature ◽  
Moisture Removal ◽  
Humidity Ratio ◽  
Desiccant Wheel ◽  
Operational Conditions ◽  
Removal Capacity ◽  
Air Inlet ◽  
Theoretical Performance

Abstract— Silica gel is a substance commonly used in desiccant wheel, which in turn is used in many applications to reduce moisture from the supplied air to a specific space. In this research,  the effect of different operational conditions on the performance of silica gel wheel were studied. The desiccant wheel, which has been used, has a diameter of 55 cm and thickness of 20 cm. It contains 34 kg of silica gel and rotate at a speed of 30 rph. The theoretical performance coefficients of the desiccant wheel which have been studied include ,moisture removal capacity(MRC),dehumidification performance(DCOP),latent coefficient of performance (COPlat), and desiccant wheel effectiveness(ϵ_d). The theoretical investigation of these coefficients was done by using Novel Aire Technology software program (Simulation program of desiccant wheel) (2012). While the operational conditions like process air (humid air)inlet temperature between(30 to 43.4)0C, process air inlet humidity ratio between (0.011 to 0.019)kg/kgdry air ,regeneration air inlet temperature between (56.5 to 70)0C,and process air mass flow rate between(0.0814 to 0.199)kg/s. The results shows that the effectiveness and the moisture removal capacity have the same behavior increase with the increasing in mass flow rate from(0.0814 to 0.199) kg/s, humidity ratio from(11 to19)g/kgdry air, and regeneration air temperature from(56 t0 70)oC. But they reduces with increasing of inlet process air temperature from(30 to43.4)oC..

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